CH706519A1 discloses a method for operating a drive-train of a working machine, in which the drive motor is an internal combustion engine and the internal combustion engine is controlled by means of a rotational speed regulating system. This ensures that the rotational speed of the drive unit can be kept almost constant regardless of the load, for example in order to operate a hydraulic pump in a uniform manner.
Whereas rotational speed regulation is found to be advantageous for auxiliary power takeoffs in working machines, for example for operating the pump of the working hydraulic system, rotational speed regulation has a negative influence on the driving behavior of the vehicle, particularly when shifting gears or shifting a converter bridging clutch of a hydrodynamic torque converter, since the vehicle undergoes an acceleration during the shifting process.